U.S. patent application number 17/274315 was filed with the patent office on 2021-11-04 for base station, user equipment, and transmission method.
This patent application is currently assigned to NTT DOCOMO, INC.. The applicant listed for this patent is NTT DOCOMO, INC.. Invention is credited to Tianyang Min, Hideaki Takahashi, Tooru Uchino.
Application Number | 20210345276 17/274315 |
Document ID | / |
Family ID | 1000005766674 |
Filed Date | 2021-11-04 |
United States Patent
Application |
20210345276 |
Kind Code |
A1 |
Uchino; Tooru ; et
al. |
November 4, 2021 |
BASE STATION, USER EQUIPMENT, AND TRANSMISSION METHOD
Abstract
A base station includes a receiving unit that receives, from an
external system, a reference time of the external system; a control
unit that generates, based on the reference time of the external
system, association information for a user equipment to calculate
the reference time of the external system to which the user
equipment belongs; and a transmitting unit that transmits the
association information to the user equipment.
Inventors: |
Uchino; Tooru; (Chiyoda-ku,
Tokyo, JP) ; Min; Tianyang; (Tokyo, JP) ;
Takahashi; Hideaki; (Chiyoda-ku, Tokyo, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
NTT DOCOMO, INC. |
Tokyo |
|
JP |
|
|
Assignee: |
NTT DOCOMO, INC.
Tokyo
JP
|
Family ID: |
1000005766674 |
Appl. No.: |
17/274315 |
Filed: |
November 1, 2018 |
PCT Filed: |
November 1, 2018 |
PCT NO: |
PCT/JP2018/040777 |
371 Date: |
March 8, 2021 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04W 56/0015
20130101 |
International
Class: |
H04W 56/00 20060101
H04W056/00 |
Claims
1. A base station comprising: a receiving unit that receives, from
an external system, a reference time of the external system; a
control unit that generates, based on the reference time of the
external system, association information for a user equipment to
calculate the reference time of the external system to which the
user equipment belongs; and a transmitting unit that transmits the
association information to the user equipment.
2. The base station according to claim 1, wherein the receiving
unit receives, from each external system of a plurality of external
systems, a reference time of the external system, and wherein the
control unit generates, for each external system of the plurality
of external systems, association information by generating
information for the user equipment to calculate the reference time
of the external system, by associating the generated information
with an identifier of the external system, and by including the
generated information and the associated identifier of the external
system.
3. The base station according to claim 1, wherein the receiving
unit receives, from each external system of a plurality of external
systems, a reference time of the external system and an identifier
of user equipment that belongs to the external system, wherein the
control unit generates, for each user equipment of one or more
units of user equipment belonging to the base station, association
information for the user equipment to calculate a reference time of
the external system to which the user equipment belongs, and
wherein the transmitting unit transmits the association information
to each user equipment of the one or more units of the user
equipment belonging to the base station.
4. A user equipment comprising: a receiving unit that receives
association information for calculating a reference time of an
external system; a control unit that calculates the reference time
of the external system based on the association information; and a
transmitting unit that transmits the calculated reference time.
5. The user equipment according to claim 4, wherein the receiving
unit receives, as the association information, association
information including, for each external system of a plurality of
external systems, information for the user equipment to calculate a
reference time of the external system and an identifier of the
external system associated with the information, and wherein the
control unit extracts, from the association information, the
information for the user equipment to calculate the reference time
of the external network to which the user equipment belongs, and
the control unit calculates the reference time of the external
network to which the user equipment belongs, by comparing (i) an
identifier, the identifier being stored in the user equipment, of
the external system to which the user equipment belongs and (ii) an
identifier of each external system included in the association
information.
6. A transmission method comprising: receiving, from an external
system, a reference time of the external system; generating, based
on the reference time of the external system, association
information for a user equipment to calculate the reference time of
the external system to which the user equipment belongs; and
transmitting the association information to the user equipment.
Description
TECHNICAL FIELD
[0001] The present invention relates to a base station, user
equipment, and a transmission method in a radio communication
system.
BACKGROUND ART
[0002] In 3GPP (3rd Generation Partnership Project), a study has
been progressed for a radio communication method called NR (New
Radio) or 5G in order to further increase capacity of a system,
further increase a data transmission rate, and further reduce
latency in a radio section (e.g., Non-Patent Document 1). For NR,
various radio technologies have been studied in order to meet the
requirement of achieving throughput of 10 Gbps or more and reducing
the latency of the radio section to be less than or equal to 1
ms.
[0003] Currently, in 3GPP Release 16, TSN (Time Sensitive
Networking)/URLLC has been discussed. URLLC aims to achieve high
reliability and low-latency communication (Ultra-Reliable and
Low-Latency Communication).
[0004] URLLC mainly targets services such as traffic control and
remote control that require both high reliability and low latency.
Examples of URLLC use cases include automobile driving control and
traffic control; robot control and 3D connection with a drone or
the like; and remote surgery.
[0005] All of the above-described use cases require high
reliability and low latency, and it is assumed that the radio
systems used therein are used mainly for the exchange of control
signals. Accordingly, in 5G, strict conditions on reliability, low
latency, and mobility are required for URLLC, instead of requiring
a high transmission rate and multiple terminal connections.
[0006] In 3GPP, for URLLC, the following are set as specific target
values to be achieved: radio section latency of less than or equal
to 1 ms; and a packet reception success probability of greater than
or equal to 99.999% when 32 bytes of packets are transmitted.
[0007] In New Radio(NR), a plurality of mutually different types of
Orthogonal Frequency Division Multiplexing (OFDM) subcarrier
spacing (15, 30, 60, 120, 240 kHz) is adopted, as a technique for
meeting the requirements of URLLC. By using large subcarrier
spacing, such as 240 kHz, a frequency bandwidth per subcarrier is
increased, and the same amount of information can be transmitted in
a shorter time. As a result, a transmission time of a radio signal
can be reduced, and the latency can be reduced.
RELATED ART DOCUMENT
Non-Patent Document
[0008] Non-Patent Document 1: 3GPP TR 22.804 V16.1.0 (2018-09)
[0009] Non-Patent Document 2: 3GPP TSG-RAN WG2 Meeting #103-Bis,
R2-1813967, Chengdu, China, 8th-12th, Oct. 2018
SUMMARY OF THE INVENTION
Problem to be Solved by the Invention
[0010] Currently, in 3GPP, interworking between a 5G system and a
TSN introduced in a factory or the like has been studied.
[0011] It is assumed that multiple independent reference times are
maintained in multiple factories. However, with current broadcast
information specified in 3GPP, a 3GPP network is allowed to signal
only information of single common time to user equipment.
[0012] There is a need for a technique that allows, in a 3GPP
network, the 3GPP network to signal at least one reference time
other than its own reference time to user equipment.
Means for Solving the Problem
[0013] According to an aspect of the present invention, there is
provided a base station including a receiving unit that receives,
from an external system, a reference time of the external system; a
control unit that generates, based on the reference time of the
external system, association information for a user equipment to
calculate the reference time of the external system to which the
user equipment belongs; and a transmitting unit that transmits the
association information to the user equipment.
Advantage of the Invention
[0014] According to an embodiment of the present invention, there
is provided a technique that allows, in a 3GPP network, the 3GPP
network to signal at least one reference time other than the
reference time maintained by the 3GPP network itself to user
equipment.
BRIEF DESCRIPTION OF DRAWINGS
[0015] FIG. 1 is a diagram illustrating an example of a requirement
on an accuracy of synchronization;
[0016] FIG. 2 is a diagram illustrating an example of a time
synchronization process;
[0017] FIG. 3 is a diagram illustrating an example of a transparent
approach;
[0018] FIG. 4 is a diagram illustrating an example of a black box
approach;
[0019] FIG. 5 is a diagram illustrating an example of a
configuration of a network system;
[0020] FIG. 6 is a diagram illustrating an example of broadcast
information;
[0021] FIG. 7 is a diagram illustrating an example of a reference
time transmission process;
[0022] FIG. 8 is a diagram illustrating an example of a functional
configuration of user equipment 10.
[0023] FIG. 9 is a diagram illustrating an example of a functional
configuration of a base station 20; and
[0024] FIG. 10 is a diagram illustrating an example of a hardware
configuration of the user equipment 10 and the base station 20.
EMBODIMENTS OF THE INVENTION
[0025] In the following, embodiments of the present invention (the
embodiment) are described with reference to the drawings. Note that
the embodiments described below are merely examples, and
embodiments to which the present invention is applied are not
limited to the following embodiments.
[0026] A radio communication system in the following embodiments is
basically assumed to conform to NR. However, this is an example,
and the radio communication system in the embodiment may conform,
in part or in whole, to a radio communication system other than NR
(e.g., LTE).
[0027] Currently, in 3GPP, interworking between a 5G system and a
TSN introduced in a factory or the like has been studied.
[0028] As described in Non-Patent Document 2, currently,
implementation of interworking between a TSN and a 5G system of
3GPP has been studied. In Non-Patent Document 2, as a method of
implementing interworking between the TSN and the 5G system of
3GPP, two methods have been studied, one called a transparent
approach and the other called a black box approach. In the
following, outlines of the transparent approach and the block box
approach are described. The following transparent approach and the
black box approach assume time synchronization processing between a
master clock and a slave clock specified in the Precision Time
Protocol (PTP). Accordingly, first, an outline of the PTP time
synchronization process is described with reference to FIG. 2.
[0029] FIG. 2 is a diagram illustrating an example of time
synchronization processing between a master clock and a slave
clock. As illustrated in FIG. 2, four types of timestamps are
exchanged between the master and the slave, which are individually
referred to as T1, T2, T3, and T4. These timestamps are required
for an offset calculation of the slave clock.
[0030] The first timestamp T1 is an exact time at which a Sync
message was sent from the master. The time at which the Sync
message is transmitted at an Ethernet port is denoted as T1. T1 is
transmitted from the master to the slave using a follow-up
message.
[0031] The second timestamp T2 is an exact time at which the slave
receives the Sync message.
[0032] The third timestamp T3 is an exact time at which a Delay
Request message is transmitted from the slave.
[0033] The fourth timestamp T4 is an exact time at which the master
receives the Delay Request message from the slave. T4 is
transmitted to the slave using a Delay Response message.
[0034] Here, it is assumed that a propagation delay from the master
to the slave is assumed to be equal to a propagation delay from the
slave to the master (the link is symmetric). In this case, an
offset between a time maintained by the clock of the slave and a
time maintained by the clock of the master can be calculated as
follows.
Offset=(Time maintained by the clock of the slave)-(time maintained
by the clock of the master)=T2-T1-(the propagation delay from the
master to the
slave)=T2-T1-((T2-T1)+(T4-T3))/2=((T2-T1)-(T4-T3))/2.
[0035] In the calculation of the above-described offset, the link
is assumed to be symmetric. If the link is asymmetric,
((T2-T1)+(T4-T3)/2 is an average of the propagation delay from the
master to the slave and the propagation delay from the slave to the
master.
[0036] Since (Time maintained by the clock of the master)=(the time
maintained by the clock of the slave)-offset, the time
synchronization between the master clock and the slave clock can be
achieved by calculating the above-described offset.
[0037] Next, an outline of the transparent approach shown in
Non-Patent Document 2 is described.
[0038] (Transparency Approach)
[0039] In this method, the user equipment receives a plurality of
Precision Time Protocol (PTP) packets through radio, including an
accurate reference time, and the received plurality of PTP packets
are transferred to all devices connected to an Ethernet port of the
user equipment. As illustrated in FIG. 3, several master ports
(indicated by M) of the clock source need to be mapped to slave
ports (indicated by S) of multiple devices.
[0040] In this case, the 3GPP system serves as a "transparent
switch" in the IEEE, and the "transparent switch" updates the
"correction Time (CT)" header field of the PTP packet in the
direction from the master to the slave and in the direction from
the slave to the master. The user equipment (UE) and the base
station (gNB) are required to update the CT to include the time
that the PTP packet is held in the UE/gNB (which is referred to as
"residence time"). In order to meet the 1 microsecond requirement
for time synchronization, the residence time is to be updated in
the PTP packet at the time of transmission.
[0041] Here, in the transparent approach, a detailed packet
inspection is required to update the "correctionTime" field just
before a PTP packet is forwarded in the uplink traffic and the
downlink traffic. For performing accurate CT update, PTP packets
are required to be prioritized so that they are transmitted with
known delays. Furthermore, latency by HARQ retransmission and a
propagation delay with radio need to be considered for updating the
CT, and the estimated CT becomes uncertain.
[0042] Accordingly, due to the uncertainty of the residence time,
the transparent approach is unable to achieve the synchronization
accuracy of less than 1 microsecond.
[0043] Next, an outline of the black box approach is described with
reference to FIG. 4.
[0044] In this approach, as illustrated in FIG. 4, a TSN provides
an accurate reference time to a 5G system of 3GPP. The 5G system of
3GPP serving as a black box corresponds to the "Boundary Clock
(BC)" in IEEE and serves as a master clock for all connected nodes.
A reference time maintained by user equipment is delivered as PTP
packets to all devices connected to an Ethernet port.
[0045] In a black box method, the precise time obtained from the
TSN can be delivered by the 5G system of 3GPP to all units of user
equipment connected to the 5G system of 3GPP. The black box
approach may achieve 1 microsecond synchronization accuracy.
[0046] Furthermore, in the black box approach, the 3GPP system is
independent of the IEEE system and the 3GPP system can maintain
accurate time within the 3GPP system.
[0047] (Problems)
[0048] In FIG. 4, a reference time is provided from one master
clock to a base station of a 3GPP system. In practice, however, a
base station of the 3GPP system is assumed to receive multiple
reference times by connecting to multiple systems (multiple master
clocks) having different clocks.
[0049] For example, as illustrated in FIG. 5, it is assumed that
systems of multiple factories (Factories A and B in FIG. 5) exist,
and each factory provides a reference time from its own master
clock. Here, in the example of FIG. 5, the number of factory
systems is two. However, the number of factory systems is not
limited to two. The number of factory systems may be one, or the
number of factory systems may be greater than or equal to three. In
the situation illustrated in FIG. 5, a case is assumed in which
units of user equipment 10 belonging to different factory systems
are provided with reference times from different master clocks.
Namely, the user equipment 10 belonging to a factory A is provided
with a reference time from a master clock of the factory A, and the
user equipment 10 belonging to a factory B is provided with a
reference time from a master clock of the factory B. In this case,
time synchronization is established among multiple units of the
user equipment 10 in factory A. Additionally, time synchronization
is established among multiple units of the user equipment 10 in
factory B. However, time synchronization need not be established
between the user equipment 10 in the factory A and the user
equipment 10 in the factory B.
[0050] In Release 15 NR, similar to LTE, time information is
specified as broadcast information. FIG. 6 is a diagram
illustrating a system information block (SIBS), as broadcast
information indicating time information.
[0051] As illustrated in FIG. 6, in the current broadcast
information, the 3GPP network is allowed to signal only information
on single common time to the user equipment 10. Accordingly, if the
current broadcast information is to be used, the 3GPP network is
unable to signal, to the user equipment 10, a reference time other
than the reference time maintained by the 3GPP network.
[0052] As a method for solving this problem, a method can be
considered in which additional information is signaled from the
3GPP network to the user equipment 10, so that the user equipment
10 can obtain at least one reference time provided by at least one
clock other than the reference time maintained by the 3GPP network.
In the following, a method 1 and a method 2 are described that are
for signaling additional information from the 3GPP network to the
user equipment 10.
[0053] (Method 1)
[0054] In Method 1, the 3GPP network signals, to the user equipment
10, association information defining correspondence between the
reference time maintained by the 3GPP network and a reference time
of another system. The user equipment 10 that receives the
association information compares an identifier of the other system
to which the user equipment 10 belongs (e.g., the system of the
factory A or the system of the factory B) with an identifier of at
least one system included in the received association information,
and the user equipment 10 extracts the information for calculating
the reference time of the other system to which the user equipment
10 belongs.
[0055] The 3GPP network may signal, as the above-described
association information, the identifier of the other system and
information for calculating the reference time of the other system
from the reference time maintained by the 3GPP network. For
example, the information for calculating the reference signal of
the other system from the reference signal maintained by the 3GPP
network may be an offset between the reference time maintained by
the 3GPP network and the reference time of the other system.
[0056] Alternatively, for example, the information for calculating
the reference time of the other system from the reference time
maintained by the 3GPP network may be a function for calculating
the reference time of the other system with the reference time
maintained by the 3GPP network as a variable.
[0057] Alternatively, a database including at least one
correspondence, among an identifier of another system, the
reference time maintained by the 3GPP network, and a reference time
of the other system, may be prepared in each of the user equipment
10 and the 3GPP network. The 3GPP network may transmit, as the
above-described association information, an identifier indicating
one of the above-described at least one correspondences to the user
equipment 10, and the user equipment 10 may calculate the reference
time of the other system, based on the received identifier.
[0058] The association information may be signaled from the 3GPP
network to the user equipment 10 as a message of a non-access
stratum layer (NAS), or it may be signaled as a message of an
access stratum layer (AS), such as an RRC message.
[0059] (Method 2)
[0060] In Method 2, the 3GPP network identifies the system of the
at least one other system (for example, the system of the factory A
or the system of the factory B) to which the user equipment 10 (or
a PTP endpoint connected to the user equipment 10) belongs, and the
3GPP network signals, to the user equipment 10, association
information for the user equipment 10 to calculate a reference time
of the identified system.
[0061] The 3GPP network (the base station 20) may signal, in
advance, at least one identifier for identifying at least one of
the other systems. In this case, the 3GPP network may include, in
the association information, the identifier of the above-described
identified system, and the 3GPP network may transmit the
association information to the user equipment 10. The user
equipment 10 that receives the association information may
identify, based on the identifier included in the association
information, the system to which the reference time calculated by
the user equipment 10 belongs. In this case, the association
information from the base station 20 may be signaled not only by
the broadcast information, but also by a dedicated RRC message or
the like per user equipment 10 or per UE group.
[0062] The above-described identifier may be an identifier of
association information; a Network Temporary Identifier (RNTI); a
Logical Channel Identifier (LCID); a Resource Block Identifier
(RB-ID); an identifier of broadcast information; an identifier of
dedicated RRC signaling; a Slicing ID; a PLMN ID; information
representing QoS, such as QFI or QCI; an AC (Access Class); or an
identifier implicitly identified from frequency and/or time
information at which the association information is received. If an
identifier or associated information is not signaled by the base
station 20, the user equipment 10 may apply a default identifier or
default associated information. Furthermore, when multiple
reference times are signaled according to requirements on
synchronization, information for identifying the different
requirements (QoS, QFI, and the like) may be signaled.
[0063] Furthermore, as the above-described identifier, an
identifier that has already been assigned to the user equipment 10
(e.g. an identifier assigned based on contract information) may be
signaled from the base station 20 (or CN). The identifier may be
signaled when an identifier of the user equipment 10 is signaled
(e.g., RACH Msg3 or Msg 5 (e.g., an RRC setup complete message))
during an initial access, or the like.
[0064] The identifier may be exchanged and shared between multiple
base stations 20 and CN nodes. The identifier may also be provided
with an effective period, and the user equipment may request
reallocation of the identifier or extension of the effective period
if the effective period of the identifier is to expire. For
example, expiration of the effective period may imply a case in
which measurement of a time period is started from a timing at
which one or more items of valid time information is last received,
and the time period exceeds a predetermined value. Furthermore, if
an RRC connection or a connection with a CN is disconnected (for
example, an RRC connection release or detach), the identifier may
be discarded or maintained (an indication from the base station 20
may specify whether it is discarded or maintained). Furthermore,
when an identifier is to be changed or updated, in order to avoid
discrepancy between the base station 20 (or CN) and the user
equipment 10, a handover (reconfigurationWithSync) or disconnection
of the RRC connection (RRC connection release) may be executed.
[0065] (Operation Example)
[0066] Next, an example of an operation of time synchronization
processing according to an embodiment is described with reference
to FIG. 7. In step S101, the base station 20 of the 3GPP network
executes time synchronization processing with the Master of the
factory A that maintains the master clock of the system of the
factory A, and the base station 20 obtains a reference time A of
the system of the factory A.
[0067] In step S103, the base station 20 of the 3GPP network
performs time synchronization processing with the Master of the
factory B that maintains the master clock of the system of the
factory B, and the base station 20 obtains a reference time B of
the system of the factory B.
[0068] In step S105, the base station 20 generates information A
for the user equipment 10 to calculate the reference time A of the
system of the factory A and associates the information A with the
identifier A of the system of the factory A. In addition, the base
station 20 generates information B for the user equipment 10 to
calculate the reference time B of the system of the factory B and
associates the information B with the identifier B of the system of
the factory B. The base station 20 generates association
information including the information A for the user equipment 10
to calculate the reference time A of the system of the factory A
and the identifier A associated with the information A; and
including the information B for the user equipment 10 to calculate
the reference time B of the system of the factory B and the
identifier B associated with the information B.
[0069] In step S107, the base station 20 transmits the generated
associated information to the user equipment 10.
[0070] In step S109, in response to receiving the association
information from the base station 20, the user equipment 10
compares (i) an identifier for identifying the system to which the
user equipment 10 belongs (in this example, one of the system of
the factory A and the system of the factory B) that is stored by
the user equipment 10 with (ii) the identifier included in the
received association information, and then the user equipment 10
obtains the information for calculating the reference time of the
system to which the user equipment 10 belongs.
[0071] For example, suppose that the identifier stored in the user
equipment 10 is the identifier A. In this case, the user equipment
10 extracts the information for calculating the reference time A of
the system of the factory A from the association information, and
the user equipment 10 calculates the reference time A of the system
of the factory A. Subsequently, in step S111, the user equipment 10
transmits the calculated reference time A of the system of the
factory A to the slave of the factory A.
[0072] In step S109, suppose that the identifier stored in the user
equipment 10 is the identifier B. In this case, the user equipment
10 extracts the information for calculating the reference time B of
the system of the factory B from the association information, and
the user equipment 10 calculates the reference time B of the system
of the factory B. Subsequently, in step S111', the user equipment
10 transmits the calculated reference time B of the system of the
factory B to the slave of the factory B.
[0073] By the above-described processing, time synchronization can
be established within the system of the factory A and/or the system
of the factory B.
[0074] (Device Configurations)
[0075] Next, examples of functional configurations of the user
equipment 10 and the base station 20 for executing the
above-described procedures are described. The user equipment 10 and
the base station 20 are provided with all of the functions
described in the embodiments. However, the user equipment 10 and
the base station 20 may include only some of the functions
described in the embodiments. The user equipment 10 and the base
station 20 may be collectively referred to as a communication
device.
[0076] <User Equipment>
[0077] FIG. 8 is a diagram illustrating an example of a functional
configuration of the user equipment 10. As illustrated in FIG. 8,
the user equipment 10 includes a transmitting unit 110, a receiving
unit 120, a control unit 130, and a data storage unit 140. The
functional configuration illustrated in FIG. 8 is only one example.
The functional division and the names of the functional units may
be any division and name, provided that the operation according to
the embodiments can be executed. The transmitting unit 110 may be
referred to as a transmitter, and the receiving unit 120 may be
referred to as a receiver.
[0078] The transmitting unit 110 creates a transmission signal from
the transmission data and transmits the transmission signal through
radio. The transmitting unit 110 may form one or more beams. The
receiving unit 120 receives various types of signals through radio
and obtains a higher layer signal from the received physical layer
signal.
[0079] The control unit 130 controls the user equipment 10. The
function of the control unit 130 related to the transmission may be
included in the transmitting unit 110, and the function of the
control unit 130 related to the reception may be included in the
receiving unit 120. For example, the configuration information is
stored in the data storage unit 140. The configuration information
related to the transmission may be stored in the transmitting unit
110, and the configuration information related to the reception may
be stored in the receiving unit 120.
[0080] For example, the receiving unit 120 receives association
information defining a correspondence between a reference time
maintained by a 3GPP network and a reference time of another system
from the base station 20, and the receiving unit 120 transmits the
received association information to the control unit 130. The
control unit 130 extracts, from the association information,
information for calculating the reference time of the other system
to which the user equipment 10 belongs by comparing the identifier
of the other system to which the user equipment 10 belongs (e.g.,
the system of the factory A or the system of the factory B) and the
identifier of the at least one system included in the received
association information, and then the control unit 130 calculates
the reference time of the other system. The control unit 130 causes
the transmitting unit 110 to transmit the calculated reference time
of the other system.
[0081] <Base Station 20>
[0082] FIG. 9 is a diagram illustrating an example of a functional
configuration of the base station 20. As illustrated in FIG. 9, the
base station 20 includes a transmitting unit 210, a receiving unit
220, a control unit 230, and a data storage unit 240. The
functional configuration illustrated in FIG. 9 is only one example.
The functional division and the names of the functional units may
be any division and names, provided that the operation according to
the embodiments can be executed. The transmitting unit 210 may be
referred to as a transmitter, and the receiving unit 220 may be
referred to as a receiver.
[0083] The transmitting unit 210 includes a function of generating
a signal to be transmitted to the user equipment 10 and
transmitting the signal through radio. Furthermore, the
transmitting unit 210 forms one or more beams. The receiving unit
220 includes a function for receiving various types of signals
transmitted from the user equipment 10 and obtaining information of
a higher layer, for example, from the received signal. The
receiving unit 220 includes a measuring unit that performs
measurement of the received signal and obtains the received power,
etc.
[0084] The control unit 230 controls the base station 20. The
function of the control unit 230 related to the transmission may be
included in the transmitting unit 210, and the function of the
control unit 230 related to the reception may be included in the
receiving unit 220. For example, the configuration information is
stored in the data storage unit 240. The configuration information
related to the transmission may be stored in the transmitting unit
210, and the configuration information related to the reception may
be stored in the receiving unit 220.
[0085] For example, the receiving unit 220 performs time
synchronization processing with another system (e.g., a system of
factory A and a system of factory B) to which the user equipment 10
belongs, the receiving unit 220 obtains a reference time of the
other system, and the receiving unit 220 transmits the reference
signal to the control unit 230. The control unit 230 generates
association information by generating information for the user
equipment 10 to calculate the reference time of the other system to
which the user equipment 10 belongs based on the reference time of
the other system and associating the identifier of the other system
with the generated information. The control unit 230 transmits the
association information to the transmitting unit 210, and the
transmitting unit 210 transmits the association information to the
user equipment 10.
[0086] <Hardware Configuration>
[0087] The block diagrams (FIG. 8 to FIG. 9) used for the
description of the above embodiments illustrate blocks of
functional units. These functional blocks (components) are
implemented by any combination of at least one of hardware and
software. In addition, the implementation method of each functional
block is not particularly limited. That is, each functional block
may be implemented using a single device that is physically or
logically combined, or may be implemented by directly or indirectly
connecting two or more devices that are physically or logically
separated (e.g., using wire, radio, etc.) and using these multiple
devices. The functional block may be implemented by combining
software with the above-described one device or the above-described
plurality of devices.
[0088] Functions include, but are not limited to, judgment,
decision, determination, computation, calculation, processing,
derivation, research, search, verification, reception,
transmission, output, access, resolution, choice, selection,
establishment, comparison, assumption, expectation, deeming,
broadcasting, notifying, communicating, forwarding, configuring,
reconfiguring, allocating, mapping, assigning, etc. For example, a
functional block (component) that functions to transmit is called a
transmitting unit or a transmitter. In either case, as described
above, the implementation method is not particularly limited.
[0089] For example, the base station 20, the user equipment 10, or
the like in an embodiment of the present invention may function as
a computer for performing a process of radio communication method
according to the present disclosure. FIG. 10 is a diagram
illustrating an example of a hardware configuration of the base
station 20 and the user equipment 10 according to an embodiment of
the present disclosure. Each of the base station 20 and the user
equipment 10 described above may be physically configured as a
computer device including a processor 1001, a memory 1002, a
storage 1003, a communication device 1004, an input device 1005, an
output device 1006, a bus 1007, and the like.
[0090] In the following description, the term "device" can be read
as a circuit, device, unit, or the like. The hardware configuration
of each of the base station 20 and the user equipment 10 may be
configured to include each device depicted, or may be configured
without including some devices.
[0091] Each function in each of the base station 20 and the user
equipment 10 is implemented such that predetermined software
(program) is read on hardware such as the processor 1001, the
memory 1002 and the like, and the processor 1001 performs an
operation and controls communication by the communication device
1004 and at least one of reading and writing of data in the memory
1002 and the storage 1003.
[0092] For example, the processor 1001 operates an operating system
and controls the entire computer. The processor 1001 may be
configured with a central processing unit (CPU) including an
interface with a peripheral device, a control device, an operation
device, a register, and the like. For example, the above-described
control unit 130, the control unit 230, and the like may be
implemented by the processor 1001.
[0093] Furthermore, the processor 1001 reads a program (program
code), a software module, data, or the like from at least one of
the storage 1003 and the communication device 1004 out to the
memory 1002, and executes various types of processes according to
them. A program causing a computer to execute at least some of the
operations described in the above embodiments is used as the
program. For example, the control unit 130 of the base station 20
illustrated in FIG. 8 may be implemented by a control program which
is stored in the memory 1002 and operates on the processor 1001.
Furthermore, for example, the control unit 230 of the user
equipment 10 illustrated in FIG. 9 may be implemented by a control
program which is stored in the memory 1002 and operates on the
processor 1001. Various types of processes are described to be
executed by one processor 1001 but may be executed simultaneously
or sequentially by two or more processors 1001. The processor 1001
may be implemented by one or more chips. The program may be
transmitted from a network via an electric communication line.
[0094] The memory 1002 is a computer readable recording medium and
configured with at least one of a read only memory (ROM), an
erasable programmable ROM (EPROM), an electrically erasable
programmable ROM (EEPROM), a random access memory (RAM), and the
like. The memory 1002 is also referred to as a "register," a
"cache," a "main memory," or the like. The memory 1002 can store
programs (program codes), software modules, or the like which are
executable for carrying out the communication method according to
an embodiment of the present disclosure.
[0095] The storage 1003 is a computer-readable recording medium and
may be configured with, for example, at least one of an optical
disk such as a compact disc ROM (CD-ROM), a hard disk drive, a
flexible disk, a magneto-optical disk (for example, a compact disk,
a digital versatile disk, or a Blu-ray (registered trademark) disc,
a smart card, a flash memory (for example, a card, a stick, or a
key drive), a floppy (registered trademark) disk, a magnetic strip,
and the like. The storage 1003 is also referred to as an "auxiliary
storage device." The above-described storage medium may be, for
example, a database, a server, or any other appropriate medium
including at least one of the memory 1002 and the storage 1003.
[0096] The communication device 1004 is hardware (a transmitting
and receiving device) for performing communication between
computers via at least one of a wired network and a wireless
network and is also referred to as a "network device," a "network
controller," a "network card," a "communication module," or the
like. The communication device 1004 may be configured to include a
high frequency switch, a duplexer, a filter, a frequency
synthesizer, and the like to implement at least one of frequency
division duplex (FDD) and time division duplex(TDD). For example,
transmitting and receiving antennas, an amplifier, a transceiver, a
transmission line interface, and the like may be implemented by the
communication device 1004. The transceiver may be implemented such
that a transmitter and a receiver are physically or logically
separated.
[0097] The input device 1005 is an input device that receives an
input from the outside (such as a keyboard, a mouse, a microphone,
a switch, a button, a sensor, or the like). The output device 1006
is an output device that performs an output to the outside (for
example, a display, a speaker, an LED lamp, or the like). The input
device 1005 and the output device 1006 may be integrally configured
(for example, a touch panel).
[0098] The devices such as the processor 1001 and the memory 1002
are connected by the bus 1007 to communicate information with each
other. The bus 1007 may be configured with a single bus or may be
configured with different buses between the devices.
[0099] Furthermore, each of the base station 20 and the user
equipment 10 may be configured to include hardware such as a
microprocessor, a digital signal processor (DSP), an application
specific integrated circuit (ASIC), a programmable logic device
(PLD), or a field programmable gate array (FPGA), or all or some of
the functional blocks may be implemented by hardware. For example,
the processor 1001 may be implemented by at least one of these
pieces of hardware.
Conclusion of the Embodiments
[0100] As described above, according to the embodiments, there is
provided a base station including a receiving unit that receives,
from an external system, a reference time of the external system; a
control unit that generates, based on the reference time of the
external system, association information for a user equipment to
calculate the reference time of the external system to which the
user equipment belongs; and a transmitting unit that transmits the
association information to the user equipment.
[0101] According to the above-described configuration, the base
station can obtain a reference time of an external system other
than the reference time maintained by the base station itself from
the external system and transmit the reference time to the user
equipment. Namely, the communication system formed of the base
station and the user equipment can be caused to function as a
boundary clock.
[0102] The receiving unit may receive, from each external system of
a plurality of external systems, a reference time of the external
system, and the control unit may generate, for each external system
of the plurality of external systems, association information by
generating information for the user equipment to calculate the
reference time of the external system, by associating the generated
information with an identifier of the external system, and by
including the generated information and the associated identifier
of the external system.
[0103] According to the above-described configuration, even if
there are multiple external systems, the base station can obtain
the reference time of each external system and transmit the
information for the user equipment belonging to the external system
to calculate the reference time of the external system.
[0104] The receiving unit may receive, from each external system of
a plurality of external systems, a reference time of the external
system and an identifier of user equipment that belongs to the
external system, the control unit may generate, for each user
equipment of one or more units of user equipment belonging to the
base station, association information for the user equipment to
calculate a reference time of the external system to which the user
equipment belongs, and the transmitting unit may transmit the
association information to each user equipment of the one or more
units of the user equipment belonging to the base station.
[0105] According to the above-described configuration, the base
station can determine an external system of a plurality of external
systems to which a specific user equipment belongs, and the base
station can transmit information for the specific user equipment to
calculate a reference time of the external system to which the
specific user equipment belongs.
[0106] Furthermore, according to the embodiments, there is provided
a user equipment including a receiving unit that receives
association information for calculating a reference time of an
external system; a control unit that calculates the reference time
of the external system based on the association information; and a
transmitting unit that transmits the calculated reference time.
[0107] According to the above-described configuration, the user
equipment can obtain information for calculating a reference time
of an external system other than the reference time maintained by
the base station.
[0108] The receiving unit may receive, as the association
information, association information including, for each external
system of a plurality of external systems, information for the user
equipment to calculate a reference time of the external system and
an identifier of the external system associated with the
information, and the control unit may extract, from the association
information, the information for the user equipment to calculate
the reference time of the external network to which the user
equipment belongs, and the control unit may calculate the reference
time of the external network to which the user equipment belongs,
by comparing (i) an identifier, the identifier being stored in the
user equipment, of the external system to which the user equipment
belongs and (ii) an identifier of each external system included in
the association information.
[0109] According to the above-described configuration, even if
there are multiple external systems, the user equipment can obtain
information for calculating the reference time of the external
system to which the user equipment belongs.
[0110] Furthermore, according to the embodiments, there is provided
a transmission method including: receiving, from an external
system, a reference time of the external system; generating, based
on the reference time of the external system, association
information for a user equipment to calculate the reference time of
the external system to which the user equipment belongs; and
transmitting the association information to the user equipment.
[0111] According to the above-described configuration, the base
station can obtain a reference time of an external system other
than the reference time maintained by the base station itself from
the external system and transmit the reference time to the user
equipment. Namely, the communication system formed of the base
station and the user equipment can be caused to function as a
boundary clock.
Supplemental Embodiment
[0112] The exemplary embodiment of the present invention has been
described above, but the disclosed invention is not limited to the
above embodiments, and those skilled in the art would understand
various modified examples, revised examples, alternative examples,
substitution examples, and the like. In order to facilitate
understanding of the invention, specific numerical value examples
have been used for description, but the numerical values are merely
examples, and certain suitable values may be used unless otherwise
stated. The classification of items in the above description is not
essential to the present invention. Matters described in two or
more items may be combined and used if necessary, and a matter
described in one item may be applied to a matter described in
another item (unless inconsistent). The boundary between functional
units or processing units in a functional block diagram does not
necessarily correspond to the boundary between physical parts.
Operations of a plurality of functional units may be performed
physically by one component, or an operation of one functional unit
may be physically performed by a plurality of parts. In the
processing procedure described in the embodiments, the order of the
processes may be changed as long as there is no inconsistency. For
the sake of convenience of processing description, the base station
20 and the user equipment 10 have been described using the
functional block diagrams, but such devices may be implemented by
hardware, software, or a combination thereof. Software executed by
the processor included in the base station 20 according to the
embodiment of the present invention and software executed by the
processor included in the user equipment 10 according to the
embodiment of the present invention may be stored in a random
access memory (RAM), a flash memory, a read-only memory (ROM), an
EPROM, an EEPROM, a register, a hard disk (HDD), a removable disk,
a CD-ROM, a database, a server, or any other appropriate storage
medium.
[0113] Furthermore, a notification of information is not limited to
the aspect or embodiment described in the present disclosure and
may be provided by any other method. For example, the notification
of information may be given by physical layer signaling (for
example, downlink control information (DCI) or uplink control
information (UCI)), higher layer signaling (for example, radio
resource control (RRC) signaling, medium access control (MAC)
signaling, broadcast information (master information block (MIB),
system information block (SIB)), other signals, or a combination
thereof. Furthermore, the RRC signaling may be referred to as an
RRC message and may be, for example, an RRC connection setup
message, an RRC connection reconfiguration message, or the
like.
[0114] Each aspect and embodiment described in the present
disclosure may be applied to at least one of Long Term Evolution
(LTE), LTE-advanced (LTE-A), SUPER 3G, IMT-advanced, 4G (4th
generation mobile communication system), 5G (5th generation mobile
communication system), Future Radio Access (FRA), NR (new Radio),
W-CDMA (registered trademark), GSM (registered trademark), CDMA
2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi(registered
trademark)), IEEE 802.16 (WiMAX(registered trademark)), IEEE
802.20, Ultra-WideBand (UWB), Bluetooth (registered trademark), a
system using any other appropriate system, and next generation
systems extended based on these standards. Furthermore, a plurality
of systems (e.g., a combination of at least one of LTE and LTE-A
with 5G) may be combined to be applied.
[0115] The processing procedures, the sequences, the flowcharts,
and the like of the respective aspects/embodiments described in
this specification may be reversed in order provided that there is
no contradiction. For example, the method described in the present
disclosure presents elements of various steps with an exemplary
order and is not limited to a presented specific order.
[0116] In this specification, a specific operation to be performed
by the base station 20 may be performed by an upper node in some
cases. In the network including one or more network nodes including
the base station 20, various operations performed for communication
with the user equipment 10 can be obviously performed by at least
one of the base station 20 and any network node (for example, an
MME, an S-GW, or the like is considered, but it is not limited
thereto) other than the base station 20. A case is exemplified
above in which there is one network node other than the base
station 20. The one network node may be a combination of a
plurality of other network nodes (e.g., MME and S-GW).
[0117] Information, a signal, or the like described in the present
disclosure may be output from a higher layer (or a lower layer) to
a lower layer (or a higher layer layer). Information, a signal, or
the like described in the present disclosure may be input and
output via a plurality of network nodes.
[0118] Input and output information and the like may be stored in a
specific place (for example, a memory) or may be managed through a
management table. Input and output information and the like may be
overwritten, updated, or additionally written. Output information
and the like may be deleted. Input information and the like may be
transmitted to another device.
[0119] The determination in the present disclosure may be performed
in accordance with a value (0 or 1) indicated by one bit, may be
performed in accordance with a Boolean value (true or false), or
may be performed by a comparison of numerical values (for example,
a comparison with a predetermined value).
[0120] Software can be interpreted widely to mean a command, a
command set, a code, a code segment, a program code, a program, a
subprogram, a software module, an application, a software
application, a software package, a routine, a subroutine, an
object, an executable file, an execution thread, a procedure, a
function, and the like regardless of whether software is called
software, firmware, middleware, a microcode, a hardware description
language, or any other name.
[0121] Further, software, commands, information, and the like may
be transmitted and received via a transmission medium. For example,
when software is transmitted from a web site, a server, or any
other remote source using a wired technology (such as a coaxial
cable, a fiber optic cable, a twisted pair, or a digital subscriber
line (DSL)) and a radio technology (such as infrared rays or a
microwave), at least one of the wired technology and the radio
technology are included in a definition of a transmission
medium.
[0122] Information, signals, and the like described in the present
disclosure may be indicated using any one of a variety of different
techniques. For example, data, instructions, commands, information,
signals, bits, symbols, chips, and the like which are mentioned
throughout the above description may be indicated by voltages,
currents, electromagnetic waves, magnetic particles, optical fields
or photons, or any combination thereof.
[0123] The terms described in the present disclosure and terms
necessary for understanding the present disclosure may be replaced
with terms having the same or similar meanings. For example, at
least one of a channel and a symbol may be a signal. Further, a
signal may be a message. Further, a component carrier (CC) may be
referred to as a "carrier frequency," a "cell," or the like.
[0124] The terms "system" and "network" used in the present
disclosure are used interchangeably.
[0125] Further, information, parameters, and the like described in
the present disclosure may be indicated by absolute values, may be
indicated by relative values from predetermined values, or may be
indicated by corresponding other information. For example, radio
resources may be those indicated by an index.
[0126] The names used for the above-described parameters are not
limited in any respect. Further, mathematical formulas or the like
using the parameters may be different from those explicitly
disclosed in the present disclosure. Since various channels (for
example, a PUCCH, a PDCCH, and the like) and information elements
can be identified by suitable names, various names assigned to the
various channels and the information elements are not limited in
any respect.
[0127] In the present disclosure, the terms "base station (BS),"
"radio base station," "base station device," "fixed station," "Node
B," "eNode B (eNB)," "gNodeB (gNB)," "access point," "transmission
point," "reception point," "transmission/reception point," "cell,"
"sector," "cell group," "carrier," "component carrier," and the
like can be used interchangeably. The base stations may also be
indicated by terms such as a macrocell, a small cell, a femtocell,
and a picocell.
[0128] The base station eNB can accommodate one or more (for
example, three) cells. In a case in which the base station
accommodates a plurality of cells, the entire coverage area of the
base station can be partitioned into a plurality of small areas,
and each small area can provide a communication service through a
base station subsystem (for example, a small indoor base station (a
remote radio head (RRH)). The term "cell" or "sector" refers to the
whole or a part of the coverage area of at least one of the base
station and the base station subsystem that performs a
communication service in the coverage.
[0129] In the present disclosure, the terms "mobile station (MS),"
"user terminal," "user equipment (UE)," "terminal," and the like
can be used interchangeably.
[0130] The mobile station may be referred to, by a person
ordinarily skilled in the art, as a subscriber station, a mobile
unit, a subscriber unit, a wireless unit, a remote unit, a mobile
device, a wireless device, a wireless communication device, a
remote device, a mobile subscriber station, an access terminal, a
mobile terminal, a wireless terminal, a remote terminal, a handset,
a user agent, a mobile client, a client, or some other suitable
term.
[0131] At least one of the base station and the mobile station may
be also referred to as a transmitting device, a receiving device, a
communication device, or the like. At least one of the base station
and the mobile station may be a device installed in a mobile body,
a mobile body itself, or the like. The mobile body may be a vehicle
(for example, a car, an airplane, or the like), an unmanned body
that moves (for example, a drone, an autonomous car or the like),
or a robot (manned type or unmanned type). At least one of the base
station and the mobile station includes a device which need not
necessarily move during a communication operation. For example, at
least one of the base station and the mobile station may be an
Internet of things (IoT) device such as a sensor.
[0132] Further, the base station in the present disclosure may be
replaced with a user terminal. For example, each aspect/embodiment
of the present disclosure may be applied to a configuration in
which communication between the base station and the user terminal
is replaced with communication between a plurality of units of user
equipment 10 (for example, which may be referred to as
device-to-device (D2D) or vehicle-to-everything (V2X)). In this
case, the user equipment 10 may have the functions of the base
station 20 described above. Further, the terms "uplink" and
"downlink" may be replaced with terms (for example, "side")
corresponding to inter-terminal communication. For example, an
uplink channel, a downlink channel, or the like may be replaced
with side channels.
[0133] Similarly, the user terminal in the present disclosure may
be replaced with the base station. In this case, the base station
may have the functions of the above-mentioned user terminal.
[0134] The term "determining" used in this specification may
include a wide variety of actions. For example, "determining" may
include, for example, events in which events such as judging,
calculating, computing, processing, deriving, investigating,
looking up, search, and inquiry (for example, looking up in a
table, a database, or another data structure), or ascertaining are
regarded as "determining." Further, "determining" may include, for
example, events in which events such as receiving (for example,
receiving information), transmitting (for example, transmitting
information), input, output, or accessing (for example, accessing
data in a memory) are regarded as "determining." Further,
"determining" may include, for example, events in which events such
as resolving, selecting, choosing, establishing, or comparing are
regarded as "determining." In other words, "determining" may
include events in which a certain operation is regarded as
"determining." Further, "determining" may be replaced with
"assuming," "expecting," "considering," or the like.
[0135] Terms "connected," "coupled," or variations thereof means
any direct or indirect connection or coupling between two or more
elements and may include the presence of one or more intermediate
elements between two elements which are "connected" or "coupled."
The coupling or the connection between the elements may be
physical, logical, or a combination thereof. For example,
"connection" may be replaced with "access." In a case in which used
in the present disclosure, two elements may be considered to be
"connected" or "coupled" with each other using at least one of one
or more electric wires, cables and/or a printed electrical
connection or using electromagnetic energy having a wavelength in a
radio frequency domain, a microwave region, or a light (both
visible and invisible) region as non-limiting and non-exhaustive
examples.
[0136] A reference signal may be abbreviated as RS and may be
referred to as a pilot, depending on a standard to be applied.
[0137] A phrase "based on" used in the present disclosure is not
limited to "based only on" unless otherwise stated. In other words,
a phrase "based on" means both "based only on" and "based on at
least."
[0138] Any reference to an element using a designation such as
"first," "second," or the like used in the present disclosure does
not generally restrict quantities or an order of those elements.
Such designations can be used in the present disclosure as a
convenient method of distinguishing two or more elements. Thus,
reference to the first and second elements does not mean that only
two elements can be adopted there, or the first element must
precede the second element in a certain form.
[0139] Further, "means" in the configuration of each of the above
devices may be replaced with "unit," "circuit," "device," or the
like.
[0140] When "include," "including," and variations thereof are used
in the present disclosure, these terms are intended to be
comprehensive, similar to a term "provided with (comprising)."
Further, the term "or" used in the present disclosure is intended
not to be an exclusive OR.
[0141] A radio frame may include one or more frames in the time
domain. In the time domain, each of one or more frames may be
referred to as a subframe. The subframe may further include one or
more slots in the time domain. The subframe may have a fixed time
length (for example, 1 ms) not depending on numerology.
[0142] The numerology may be a communication parameter applied to
at least one of transmission and reception of a certain signal or
channel. For example, the numerology may indicate at least one of a
subcarrier spacing (SCS), a bandwidth, a symbol length, a cyclic
prefix length, a transmission time interval (TTI), a number of
symbols per TTI, a radio frame configuration, a specific filtering
process performed in the frequency domain by a transceiver, a
specific windowing process performed in the time domain by a
transceiver, and the like.
[0143] The slot may include one or more symbols (orthogonal
frequency division multiplexing (OFDM) symbols, single carrier
frequency division multiple access (SC-FDMA) symbols, or the like)
in the time domain. The slot may be a time unit based on the
numerology.
[0144] The slot may include a plurality of mini slots. Each mini
slot may include one or more symbols in the time domain. Further,
the mini slot may be referred to as a sub-slot. The mini slot may
include fewer symbols than a slot. A PDSCH (or PUSCH) transmitted
in units of times greater than the mini slot may be referred to as
a PDSCH (or PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted
using a mini slot may be referred to as a PDSCH (or PUSCH) mapping
type B.
[0145] All of a radio frame, a subframe, a slot, a mini slot, and a
symbol indicates a time unit for transmitting a signal. As a radio
frame, a subframe, a slot, a mini slot, and a symbol, different
names corresponding to them may be used.
[0146] For example, one subframe may be referred to as a
transmission time interval (TTI: Transmission Time Interval), or a
plurality of consecutive subframes may be referred to as TTIs, or
one slot or one mini slot may be referred to as a TTI. In other
words, at least one of the subframe and the TTI may be a subframe
(1 ms) in the existing LTE, may be a period shorter than 1 ms (for
example, 1 to 13 symbols), or may be referred to as a period longer
than 1 ms. A unit representing the TTI may be referred to as slot,
a mini slot, or the like instead of the subframe.
[0147] Here, for example, the TTI refers to a minimum time unit of
scheduling in radio communication. For example, in the LTE system,
the base station performs scheduling of allocating a radio resource
(a frequency bandwidth, a transmission power, or the like which can
be used in each user equipment 10) to each user equipment 10 in
units of TTIs. The definition of the TTI is not limited
thereto.
[0148] The TTI may be a transmission time unit such as a channel
coded data packet (transport block), a code block, or a code word,
or may be a processing unit such as scheduling or link adaptation.
Further, when a TTI is provided, a time interval (for example, the
number of symbols) in which a transport block, a code block, a code
word, or the like is actually mapped may be shorter than the
TTI.
[0149] Further, when one slot or one mini slot is referred to as a
TTI, one or more TTIs (that is, one or more slots or one or more
mini slots) may be a minimum time unit of scheduling. Further, the
number of slots (the number of mini slots) forming the minimum time
unit of scheduling may be controlled.
[0150] A TTI having a time length of 1 ms may be referred to as a
common TTI (TTI in LTE Rel. 8 to 12), a normal TTI, a long TTI, a
common subframe, a normal subframe, a long subframe, a slot, or the
like. A TTI shorter than the common TTI may be referred to as a
reduced TTI, a short TTI, a partial TTI (a partial or fractional
TTI), a reduced subframe, a short subframe, a mini slot, a sub
slot, a slot, or the like.
[0151] Further, a long TTI (for example, a normal TTI, a subframe,
or the like) may be replaced with a TTI having a time length
exceeding 1 ms, and a short TTI (for example, a reduced TTI or the
like) may be replaced with a TTI having a TTI length that is less
than a TTI length of a long TTI and that is longer than or equal to
1 ms.
[0152] The resource block (RB) is a resource allocation unit in the
time domain and the frequency domain and may include one or more
consecutive subcarriers in the frequency domain. The number of
subcarriers included in an RB may be the same irrespective of a
numerology and may be, for example, 12. The number of subcarriers
included in an RB may be determined based on a numerology.
[0153] Further, a time domain of an RB may include one or more
symbols and may be a length of one slot, one mini slot, one
subframe, or one TTI. One TTI, one subframe, or the like may be
formed of one or more resource blocks.
[0154] Further, one or more RBs may be referred to as a physical
resource block (PRB), a sub carrier group (SCG), a resource element
group (REG), a PRB pair, an RB pair, or the like.
[0155] Further, the resource block may be formed of one or more
resource elements (RE). For example, one RE may be a radio resource
region of one subcarrier and one symbol.
[0156] A bandwidth part (BWP) (which may be referred to as a
partial bandwidth) may indicate a subset of consecutive common
resource blocks (RBs) for a certain numerology in a certain
carrier. Here, a common RB may be specified by an index of an RB
based on a common reference point of a carrier. A PRB may be
defined in a BWP and numbered in a BWP.
[0157] The BWP may include a BWP for UL (UL BWP) and a BWP for DL
(DL BWP). In a UE, one or more BWPs may be configured within one
carrier.
[0158] At least one of configured BWPs may be active, and the UE
need not assume that predetermined signals/channels are transmitted
and received outside an active BWP. Further, a "cell," a "carrier,"
or the like in the present disclosure may be replaced with a
"BWP."
[0159] Structures of the radio frame, the sub frame, slot, the mini
slot, and the symbol are merely examples. For example,
configurations such as the number of subframes included in a radio
frame, the number of slots per subframe or radio frame, the number
of mini slots included in a slot, the number of symbols and RBs
included in a slot or a mini slot, the number of subcarriers
included in an RB, the number of symbols in a TTI, a symbol length,
a cyclic prefix (CP) length, and the like can be variously
changed.
[0160] In the present disclosure, for example, when an article such
as "a," "an," or "the" in English is added by a translation, the
present disclosure may include a case in which a noun following the
article is the plural.
[0161] In the present disclosure, a term "A and B are different"
may mean "A and B are different from each other." Further, the term
may mean "each of A and B is different from C." Terms such as
"separated," "coupled," or the like may also be interpreted
similarly to "different."
[0162] Each aspect/embodiment described in this specification may
be used alone, in combination, or may be switched in accordance
with the execution. Further, notification of predetermined
information (for example, notification of "being X") is not limited
to being performed explicitly, but may be performed by implicitly
(for example, not notifying the predetermined information).
[0163] Further, in the present disclosure, the DL-SSB is an example
of a block including the synchronization signal and the broadcast
information in downlink. The SL-SSB is an example of a block
including the synchronization signal and the broadcast information
in sidelink.
[0164] Although the present disclosure is described above in
detail, it is obvious to those skilled in the art that the present
disclosure is not limited to the embodiments described in the
present disclosure. The present disclosure may be implemented as
revised and modified embodiments without departing from the gist
and scope of the present disclosure as set forth in claims.
Accordingly, the description of the present disclosure is for the
purpose of illustration and does not have any restrictive meaning
to the present disclosure.
LIST OF REFERENCE SYMBOLS
[0165] 10 user equipment [0166] 110 transmitting unit [0167] 120
receiving unit [0168] 130 control unit [0169] 140 data storage unit
[0170] 20 base station [0171] 210 transmitting unit [0172] 220
receiving unit [0173] 230 control unit [0174] 240 data storage unit
[0175] 1001 processor [0176] 1002 memory [0177] 1003 storage [0178]
1004 communication device [0179] 1005 input device [0180] 1006
output device
* * * * *